This project is concerned with therapeutic procedures in the use of tricyclic antidepressants (TCA's). It attempts to determine which procedures should be researched, taught, and practiced. Operationally, a survey will be made of therapeutic procedures used by psychiatrists when faced with a clinical decision regarding the possible use of a TCA. Clinical vignettes have been constructed to represent the following decision categories: (a) indications and contraindications for the use of any TCA; (b) indications for the differential use of specific TCA's; (c) dosing methods; (d) taking account of medical complications; and (e) expectations for clinical course and pharmacological action. Clinically plausible procedural decisions are presented as alternatives for each vignette. Each respondent is surveyed regarding the alternative he uses in his practice. Three types of psychiatrists will be surveyed: (a) nationally recognized experts on TCA's; (b) teacher psychiatrists in accredited departments; and (c) general psychiatric practitioners. In the expert group, items will be grouped by the extent of agreement on how to proceed. Items of greatest disparity are prima-facie topics for research. Items of greatest agreement will define what is accepted by expert informed opinion; these will be compared with responses of teachers and general psychiatric practitioners to see which definitive procedures are being taught or practiced. Needs for training, communication, and research will be better specified by these results. While the current project is concerned exclusively with the therapeutics of TCA's, future projects on this model will inquire about other classes of psychotherapeutic drugs.